Aircraft gun mount supported independently of enclosures therefor



NOV. 15, 1938. c QANDERS 2,136,825

AIRCRAFT GUN MOUNT SUPPORTED INDEPEHDENTLY OF ENCLOSURES THEREFOROriginal Filed Oct. 7, 1934 Z'mnentor John 0. 3a dersi F a QM (It prmgPatented Nov. 15, 1938 AIRCRAFT GUN MOUNT SUPPORTED INDE- gglDENTLY FENCLOSURES THERE- John C. Sanders, Seattle, Wash., assignor to Boe-' ingAircraft Company, Seattle, Wash., a corporation of Washington Originalapplication October 7, 1934, Serial No.

Divided and this application Decembe! 21, 1936, Serial No. 116,917

14 Claims.

My invention relates to an aircraft gun emplacement, and moreparticularly to a mounting for machine guns or other ordnance primarilyfor use upon airplanes, although such a mounting could be used uponlighter-than-air craft. This application is a division of my applicationSerial No. 749,040, filed October 7, 1934.

My invention is particularly intended for installation in high speedairplanes such as bombing planes, in which it is desirable to have thegun mount and the gunner enclosed to as great an extent as possible,both to avoid any appreciable increase in the air resistance of theaircraft and to permit the gunner to work effectively by shielding himfrom exposure to the air flow.

More specifically it is my object in a gun emplacement to provide astructure which will afford such protection without adding appreciablyto the weight or complicating the conventional structure of an airplane.To accomplish this object I propose to support the gun mount from thefuselage proper separately from the protective shell and its support, sothat the shell structure itself need not be of heavy construction tosupport the weight of the gun and gun mount, or to withstand thestresses created by recoil of the gun, since both of these will betransmitted directly to the fuselage.

To increase further, the aerodynamic efficiency of such a gunemplacement, as an object of my invention I provide a construction whichwill enable the gun to be withdrawn entirely from the air stream to aposition within the shell protecting the gun mount and the gunner, sothat even the resistance crfited by the gun .barrel may be eliminatedwhen the gun is not in operation.

Other objects of my invention which are inherent in the particular typeof construction which I employ will appear from a study of thespecification, in conjunction with the accompanying drawing, which showsillustrative forms of my device.

My invention here described, and defined in the appended claims,pertains not so much to the type of enclosure for the gun mount andgunner or to the particular type of gun or gun mount employed as it doesto the manner in which the gun mount is supported from and is movablewith relation to the aircraft structure, and in the manner in which thegun mount support cooperates with particular types of enclosures.

The drawing shows exemplary types of gun mount supports largely indiagrammatic illustrations, and these may be modified according to therequirements of particular installations,

while still utilizing the same principles in structurefalling within thedefinitions of the claims appended to this specification.

Figure 1 is a longitudinal section, and Figure 2 a transverse sectionfrom the inside looking forward, of the nose portion of an airplanefuselage incorporating my invention.

Figures 3 and 4 correspond to Figures 1 and 2, respectively,illustrating a modified form of my gun mount support, and Figure 5 is aview corresponding to Figure 3 of this same form, showing the gun, gunmount, and support for the latter in fully retracted position.

In modern aircraft armament some at least of the machine guns employedare of larger caliber than formerly was thought to be feasible. It hadalways been customary to use no larger than .30 caliber machine guns,but for better protection .50 caliber machine guns are now sometimesused. Such guns are not only of greater weight, but they set up recoilstresses which are considerably greater than those created by thesmaller types of guns. Accordingly the gun mount and the supportingstructure therefor must be made correspondingly heavier and more rigid.

In a high speed airplane, however, it is essential that a gun be asmobile as possible. Where a protecting shield is employed to move withthe gun, this shield, although usually of fairly large size, must alsobe readily movable in order not to impede the facility of movement ofthe gun. If the gun mount is supported directly from such an enclosure,however, the latter must be built both to support the weight of the gunand to withstand the recoil stresses set up thereby. If in addition tothis the gun is supported upon the enclosure in an eccentric position, acounterweight will ordinarily be employed, as shown in Figure 6 of myapplication Serial No. 749,040, referred to above. Because of itsconsiderable weight the enclosure for the gun,-'especially where a largecaliber gun is employed, will have an inertia which may seriously hamperthe gunner in aiming the gun quickly. I

As a solution to these difiiculties I propose to support the gun mountand the gunner directly from the fuselage, although the mount may stillbe protected by a rotative enclosure. The latter can then be made ofcomparatively light construction, and need not be counterweighted. Thusin Figures 1 and 2 I have shown the gun I projecting from the shell 4,which is rotatively mounted upon the airplane fuselage 40 through atrack 44. That portion of the fuselage 40 adjacent to the base of theshell also acts as a support for the gunner when operating the gun. Thegun mount is pivoted at 24 upon a bracket 36 which is supported in andguided for movement about the peripheral track 41, secured to thefuselage 49 behind the track 44 for the shell. Thus the gun mount andthe shell are independently supported fromthe airplane fuselage, so thatneither the weight nor the recoil stresses of the gun and the gun mountare transmitted to or through the shell 4 or its supporting means.

The shell 4, of substantially hemispherical shape, is mounted to rotateabout an axis normal to the base through its center, which maycorrespond to the longitudinal axis of the fuselage. The shell isprovided with a circular aperture disposed eccentrically of its rotativeaxis, which receives a gun shield 3, preferably of spherical shape,surrounding the gun mount and tiltable with respect to the shell on theaxis 2%. Since this axis is disposed substantially in the surface of theshell, a close fit can be made between the sphere 3 and shell 4, so thatas the gun mount support is moved about the track 41 to afford orbitalmovement of the gun mount, the shell 3 is likewise rotated.

The gun mount itself is preferably substantially the same as that shownin Figures 1 to 5 inclusive of my application Serial No. 749,040, inwhich the gun is supported for both traversing and elevational swingingmovement, and in addition for rotation about its longitudinal axis.

It will be seen that since whenever the bracket 36 is rotated about thetrack 41' the shell 3 must rotate therewith, the conjoint movement ofthese two elements is precisely the same as though the pivot 26 wereactually fixed to the shell, except that, as previously mentioned, theweight and recoil stresses of the gun are transmitted through thebracket 36, instead of through the shell and its supporting means. Inall positions, of course, the gunshield 3 will tilt about the axis 26with respect to the shell, but since this shield is of spherical shapethe shell aperture will be closed for all its rotative positions.Likewise the gun may be traversed along the sphere slot, as it wouldwere the gun mount supported from the shell rather than from. theaircraft structure directly. By rotating about its longitudinal axisthe'gun can be kept always upright, as otherwise the feed means and themeans to collect the discharged cases and links might not functionproperly.

In Figures 3 to 5 inclusive also the shell 4 is mounted to rotate withrespect to the fuselage and gunners support 40 upon a track 44, in thesame manner as it does in connection with Figures 1 and 2. Instead ofbeing provided with an eccentrically disposed aperture, however, in thismodification the shell merely has a great circle slot 49 extendingsubstantially from side to side of the shell, through which the gun Imay project. This arcuate slot 49 defines in every rotative position ofthe shell plane normal to the shell's base or to the plane of the track44.

The gun mount l0 employed is tiltable for elevational movement about anaxis l4 upon a yoke 21?, and this yoke in turn is pivoted for traversingmovement upon an axis 22 in a bracket 28 Thus when the gun is supportedas shown in Figure 3 a universal movement may be accomplished, so thatfor all rotative positions of the shell 4 the gun may be moved along theslot, although in doing so the gun may be pivoted to some extent aboutboth axes, as would be the case, for example, were the gun moved alongthe slot with the shell 4 in the position shown in Figure 4. The shell lis so mounted that, except when the gun projects through the slotprecisely axially of the shell, slight pressure of the gun against theedge of the slot 49 will rotate the shell about its axis. Thus conjointmovement of the gun and shell may be eifected with substantially thesame ease as the gun alone may be moved.

While bracket 28 may be fixed in the forward position shown in Figure 3,so that the gun always projects through the slot 49, and the shell, byreason of this engagement, always follows the movements of the gun, itwill be preferable that the arm 28 also be movable longitudinally withrespect to the fuselage 40 upon a track 49'. The bracket may be heldwith relation to the track, for instance in advanced position with thegun projecting through the slot, or in retracted position with the gunwithdrawn completely into the shell 4*, by a dog 29 carried by the arm28 With the gun withdrawn entirely into the streamline shape, as shownin Figure 5, all possible drag is avoided, and yet, if care is taken,the gun may still be fired through the slot 49 while it is in thisretracted position. When withdrawn from the slot, however, the gunbarrel will no longer engage the shell at the edge of the slot tomotivate it for rotational movement as the gun is tilted or swung, butif desired, arrangements may be made to effect appropriate rotation ofthe shell by swinging of the gun even when it is not engaged in theshell slot.

What I claim as my invention is:

1. In an aircraft body having an opening therein, a substantiallyhemispherical shell closing such opening and having a great circle slotbisecting such shell and extending substantially to the shell base ateach end, means supporting said shell directly from the aircraft bodyand guiding it for rotation through a complete circle with respectthereto about an axis through the center of its base, a bracketsupported from the aircraft structure independently of said shell andshell supporting means, and a gun mount supported by said bracket formovement of a gun supported thereby along said slot and with respect tosaid bracket in every rotative position of said shell.

2. The combination of claim 1, and a track supported in the aircraftstructure extending normal to the opening, and guiding the bracket formovement therealong, to retract the bracket and gun mount for withdrawalof the gun from the shell slot into the shell.

3. The combination of claim 1, and a track supported in the aircraftstructure extending normal to the opening, and guiding the bracket formovement therealong, to retract the bracket and gun mount for withdrawalof the gun from the shell slot into the shell, and means operable tolock the bracket against movement along the track.

4. In an aircraft structure having a planar circular opening therein, ashell, in the form of a body of revolution about an axis normal to suchopening through its center,'closing such opening, and having an aperturetherein disposed eccentrically of its generating axis, means supportingsaid shell directly from the aircraft structure and guiding it forrotation with respect to such structure about its generating axis, atrack mounted on the aircraft structure and extending peripherally aboutthe margin of said opening, a carriage guided for movement along saidtrack, a bracket carried by said carriage and projecting into saidshell, and a gun mount adapted to support a gun projecting through suchshell aperture, and mounted on said bracket for rotation therewith andwith said shell, to maintain the gun projecting through the shellaperture for various rotative positions of the shell.

5. In an aircraft structure having an opening therein, a shell in theform of a body of revolution closing such opening, and having anaperture therein disposed eccentrically of its generating axis, shellsupporting means supporting the shell directly from the aircraftstructure and guiding it for rotation with respect to such structure, agun shield closing such shell aperture, a gun mount disposed behind saidgun shield and adapted to support a gun projecting through said shield,and a bracket, supported from said aircraft structure independently ofsaid shell supporting means, supporting said gun shield and said gunmount for conjoint rotation with said shell to maintain the gunprojecting through said shield and the shield in registry with the shellaperture for various rotative positions of the shell.

6. In an aircraft structure having a planar circular opening therein, ashell, in the form of a body of revolution about an axis normal to suchopening through its center, closing such opening, and having a circularaperture therein disposed eccentrically of its generating axis, shellsupporting means supporting the shell directly from the aircraftstructure and guiding it for rotation with respect to such structureabout its generating axis, a sphere received in and closing such shellaperture, a bracket, supported from said aircraft structureindependently of said shell supporting means, supporting said sphere forrotation with said shell to maintain the sphere in registry with theshell aperture for various rotative positions of the shell, and a gunmount supported by said bracket for elevational and traversing movementwith respect to said bracket, and adapted to support a gun projectingfrom said sphere.

7. The combination of claim 6, and a track mounted on the aircraftstructure and extending peripherally about the margin of the aircraftstructure opening, and a carriage, guided for movement along said track,supporting the bracket from the aircraft structure.

8. In an aircraft body terminating at one-end in an opening disposedtransversely of the longitudinal axis of the body, an apertured shellconstituting a terminal closure for such opening, a gun mount to supporta gun projecting through the shell aperture, means supporting said gunmount directly from the aircraft body and independently of said shelland guiding said gun mount for movement with respect to the aircraftbody, means supporting said shell directly from the aircraft body andguiding it for free and unrestrained movement With respect to theaircraft body, and means to transmit movement of a gun carried by saidgun mount to said shell to motivate said shell by movement of said gunas the latter is moved in aiming.

9. In an aircraft body having a circular opening therein, an aperturedshell having a circular base closing such opening, a gun mount tosupport a gun projecting through the shell aperture, a gun mountsupporting bracket extending from the periphery of the shell baseradially inward, a track secured to the aircraft body at the peripheryof the shell base, and a carriage carrying said bracket and guided formovement along said track.

10. In an aircraft body terminating in a planar, circular openingextending transversely of the direction of flight, a substantiallyhemispherical shell constituting a terminal closure for such aperture incontinuation of the aircraft body, means supporting said shell directlyfrom the aircraft body and guiding it for rotation through a completecircle with respect thereto about an axis perpendicular to its terminus,a gun mount to support a gun projecting from said shell, and means,independent of said shell supporting means, supporting said gun mountfor projection of a gun through said shell in every rotative positionthereof, and guiding it for rotation of the guns muzzle through acomplete circle about the shells rotative axis, during the specifiedrotation of the shell.

11. In an aircraft structure having an opening therein, a shell, in theform of a body of revolution closing such opening and rotatable through360 about an axis normal to such opening through its center, and havingan aperture therein disposed eccentrically of its generating axis, shellsupporting means supporting the shell di.- rectly from the aircraftstructure and guiding it for rotation about such axis with respect tosuch structure, a bracket supported from said aircraft structureindependently of such shell supporting means, a gun mount constituting auniversal swivel supported from said bracket for tilting of the gunmount and gun in traverse and elevation, in any rotated position, anddisposed always with its swivel center in the median plane of said shellpassing through the eccentric aperture, and means guiding said bracketfor orbital revolution through 360 with said shell to maintain the gunprojecting through the shell for various rotative positions of theshell.

12. In an aircraft structure terminating at one end in an openingdisposed transversely of the longitudinal axis of the structure, a shellin the form of a body of revolution about such longitudinal axis closingsuch opening, and having an aperture therein disposed eccentrically ofits generating axis, shell supporting means supporting the shelldirectly from the aircraft structure and guiding it for rotation aboutsuch longitudinal axis with respect to such structure, a gun mountconstituting a universal swivel, and adapted to support a gun projectingthrough such shell aperture, a bracket, supported from said aircraftstructure independently of said shell supporting means, supporting saidgun mount with its swivel center always in the median plane of saidshell passing through its eccentric aperture, and means guiding saidbracket for orbital rotation with said shell to maintain the gunprojecting through the shell aperture for'various rotative positions ofthe shell.

13. In an aircraft body terminating in a complete and uninterruptedopening which is substantially circular, and which is disposedtransversely to the body's longitudinal axis, an apertured shell havinga circular base closing such opening, and rotatively mounted relative tothe body, a gun mount to support a gun projecting through the shellsaperture, and means on the body supporting the gun mount for movement ofthe gun, including its bodily displacement, with and relative to theshell. 7

14. In an aircraft structure having a planar circular opening therein, ashell, in the form of a body of revolution about an axis normal to suchbracket carried by said carriage and projecting into said shell, and agun mount, mounted on said bracket for rotation therewith and with saidshell, adapted to support and maintain a gun projecting through suchshell aperture for various rotative positions of the shell, and means tosupport the gun from the bracket for rotation about its own longitudinalaxis.

JOHN C. SANDERS.

